天然气掺氢火花点火式发动机排放性能研究

在一台天然气掺氢的火花点火发动机上,研究了掺氢比和过量空气系数对发动机排放性能的影响.结果表明,在掺氢比一定时,过量空气系数对 HC、CO、Nox 和 CO2排放有较大的影响.在相同过量空气系数下,随着掺氢比的增加,HC 排放量有所降低,特别是稀燃下的 HC 排放量大幅降低.Nox排放量随掺氢比的增加而增加,而 CO2排放量随掺氢比的增加而减少.掺氢后,发动机的稀燃极限有所提高,稀燃条件下发动机的HC、CO、CO2 和 Nox的排放量比较低.

Experimental Investigation on Emissions of a Spark-Ignition Engine Fuelled with Hydrogen Enriched Natural Gas

An experimental investigation on the influence of the different percents of hydrogen and excess air ratios on emissions characteristics of a spark-ignition engine fuelled with hydrogen enriched natural gas was conducted.The results show that excess air ratio has a remarkable effect on HC,NOx,CO,and CO2 emissions when engine is operated with a given percent of hydrogen.HC emissions decreases as increasing the percent of hydrogen at the same excess air ratio,especially under the lean-burn condition.However,NOx emission increases and CO2 concentration decreases as the percent of hydrogen increases.Adding hydrogen into natural gas can extend the lean burn limit of mixture.Engine combustion at lean mixture can get low emissions of HC,CO,CO2 and NOx.